Optical Network Configurations

[barrows]

@jabbr, Are you able to recommend a specific, single mode, 1 Gbe SFP module for use with the Sonore optical products off the top of your head?

I am interested in testing single mode fiber in my set up (Although RMAF preparations and product building is keeping me very busy right now). 

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5 hours ago, marce said:

My view on the front end supply is as long as it is a decent supply it should not make any difference to the results as the main and critical part of any power delivery system is already on the board as I explained above... One would hope

While I would agree, to a point (and to address marce's point, John Swenson has addressed the local power supply needs with great attention to detail, many separate ultra low noise/impedance linear regs for different sections, with multiple islands, etc on the main board of the opticalRendu and Signature Rendu SEoptical, and great attention to proper decoupling), the main power supply and first pre-regulator supply still needs to be as good as is possible for the best possible performance.  Although I agree with @marce, that it would be a fools errand to pay so much attention to the main supply if the local supplies were not properly engineered first.

 

As to the view of sharing measurements, such as eye pattern, etc.  This is a tricky area to get into for a manufacturer for many reasons.  Most customers would have no idea how to interpret things like this (and for those who do, great, I am not attempting to dumb you down!), and what would one compare these with?  Where are eye pattern diagrams from other products for comparisons?  And, even worse, if the eye pattern tests are not performed under the same conditions, one could be making a big mistake to compare one eye pattern diagram with another.  So, if a manufacturer shared measurements like these, it can do more harm than good.  Instead, I would suggest it is the manufacturers job to make the best product they can, and it is the users and reviewers job to evaluate the product for its performance.  Additionally, in my experience in this industry, I have seen many times when a manufacturer publishes a measurement, and then the public comes back and criticizes the measurement, suggesting that the manufacturer has been disingenuous about how they made a given measurement, creating a "controversy".  It is usually better for independent third parties to evaluate components, rather than for manufacturers to try and "prove" performance.  

I think it would be cool though, if an independent third party (reviewer) tested various Renderer's for both eye pattern on the USB data lines, and noise on the USB power lines under the same test conditions and published the results.  

I have seen HiFi News testing of USB cables with eye pattern results (I wonder how that LUSH USB cable would do on an eye pattern test...).

 

OR:  Or, one could just listen to the products.  The improvement in sound quality from the ultraRendu to the opticalRendu in the same system is not difficult to hear, for example, as those who have listened have reported.

[barrows]

5 hours ago, John769 said:

@barrows Cisco GLC-LH-SM (x 2) confirmed working  OM -> Cisco 2960.  They were cheap s/h on ebay.

 

 

 

 

Thanks, I have these bookmarked and will likely pick up a pair for testing here, but probably not until after RMAF as preparations are taking a lot of time now.  BTW folks, hope to see some of you at the Show!  We will have a really nice set up there (I hope the new venue's rooms are going to be a bit better than the old venue).

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8 minutes ago, jabbr said:

The reason the IEEE 802.3 networking standards were upgraded after 2002 was to avoid this line of reasoning

 

I was referring to customers comparing eye pattern diagrams from the USB output from different sources.  I do not think your comments are relevant to this.  My comment was in response to questions asking about the USB output.

 

While the standards which you refer to are great for professionals (or enthusiastic amateurs) well versed in the subject, i still do not believe that the average customer is such, and knows how to properly interpret such tests.  Clearly I am not referring to you here though!

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8 minutes ago, jabbr said:

Again, I don’t want to have an all encompassing discussion here, rather focus on optical Ethernet. My own impression regarding USB, which I suspect is similar to yours, is that it is the upgraded USB Vbus/power supply which makes the most difference for the DAC. 

Well, certainly the very clean USB power is an important feature of the opticalRendu.  But John has some interesting ideas RE USB signal integrity, and I would not contradict him on that (these ideas are discussed in depth elsewhere on these forums).

 

8 minutes ago, jabbr said:

My claim is that fiberoptic Ethernet compliant to the modern standards does not transmit noise from upstream servers to the DAC

Agreed, that is why we incorporated it into the systemOptique product line.

 

But we ARE getting a bit off topic here, sorry for that...  Folks, let's try and keep the discussion here to @jabbr's topic.

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4 hours ago, jabbr said:

This is is a switch, so it implements things like 802.3z (flow control) and has a routing/vlan mode but I’m not using that. 

Hi, so flow control can be defeated in the settings for this device, just trying to confirm for sure!  Thanks, B.

[barrows]

While I do not agree with Gordon Rankin on everything, I d.o agree with his position on WiFi.  In any case this podcast is a good listen:

 

https://www.audiostream.com/content/gordon-rankin-wavelength-audio-audiostream-podcast-no12

 

At Sonore we do not really recommend WiFi for those looking for best sonic performance.

[barrows]

Or, I could not bother with that and just listen to what I already do, fantastic sound with optical Ethernet isolation from all the commercial computer gear via The Signature Rendu SEoptical. 

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2 minutes ago, plissken said:

At around the 17 minute mark I now understand why other EE's take exception with Gordon.

And there are things I disagree on with him as well...  But it would be a boring world with nothing to learn if everyone, even EEs, all agreed!

 

[barrows]

Spectral distribution of noise is going to make a difference on whether it matters, or not, maybe!  It is worth noting that higher noise frequencies are easier to filter out, but that higher noise frequencies also are more likely to go airborne...

 

With optical Ethernet I worry less about such things, as long as the noisy gear (commercial computer stuff) is away from the audio system in another part of the home.  Ethernet transformers should do a pretty good job with very high frequency noises (until they are airborne), but I am not a magnetics expert.

 

Then there is the latency issue, or not...speed equals less latency: some appear to believe that less latency in transmission equals better sound quality, although the reasoning behind this belief alludes me... 

[barrows]

28 minutes ago, lmitche said:

Hi NOT FIndingit,

 

They are right there on the ebay US site. Keep looking.  Clue: there are white label Avago models as well of the same spec.

 

 

Or, they could be counterfeit.  Do not underestimate the possibility of Chinese counterfeit products at "too good to be true" prices on eBay.

[barrows]

5 hours ago, lmitche said:

Anything that is nonuniform in power demand is going to diminish our SQ.

 

Hey man, I find this discussion very worthwhile and illuminating in many ways.  But,, while I agree with the basic idea of the above, I think the statement is a bit too absolute to be (always) true, especially without objective verification.  I would suggest that we would need to establish where these power supply perturbations actually may have audible consequences, lest we drive folks down paths which may be a bit crazy, and perhaps even a waste of time and effort.

For example, i would submit that such power supply perturbations are only going to have a possibility of influencing the actual sound quality (in the analog domain, loudspeakers, or headphones) IF they make their way to the USB output.  I can accept that in the case of these power supply perturbations getting to the USB output, that they may affect sound quality.  This could be related to the USB ground, the data lines, or between the ground and power line.  I would also suggest, that even if these power supply supply perturbations are present on the power feed for the SFP module (and the same would apply to the processor chip, memory, etc, etc), some Renderers may be well enough engineered that these power supply perturbations do not make it the USB output.  I would also point out that some well equipped engineers can (and do) measure the USB output for the presence of any such problems. 

 

@jabbr, with your preference for Finisar product, do you suppose that Finisar SFP transceivers may have benefits for 1Gbe SFP (non +) as well as SFP+?

[barrows]

56 minutes ago, Superdad said:

 

Hi Barrows:

Well you can answer the question for yourself by changing power supply to an opticalModule FMC feeding an opticalRendu. Lot's of Sonore clients doing just that and reporting differences...

Hi Alex, I am trying to keep the thread generic as to "brands" and such...  Of course i use an oM (with a Sonore Power Supply of my design with single digit µVs of noise), and run SMF to my Signature Rendu SEoptical.

 

But, the power supply quality on the oM in this instance may produce improvements for other reasons: such as lowering the phase noise on the oscillator in the oM...  So I cannot for sure say that power supply perturbances caused by the SFP transceiver is the reason an improved power supply might improve audible performance.  Anyway, I was thinking more about the SFP transceiver in the Renderer side, where any power supply perturbance might have a path to the USB output (or not!).  But these are all unproven allegations as far as I am concerned, and I consider it highly speculative to suggest that they do effect sound quality, given that the only evidence of such is entirely subjective (and neither is it agreed upon) at this point.  This does not mean that these things do not effect sound quality, just that while it might be OK to speak in absolutes about such esoteric, and unproven things in the "massive" thread, at other places on AS I would prefer to keep things a little bit more down to earth.  Such that, when extreme claims are made (from a technical perspective), they are actually accompanied by some level of at least technical explanation for such, if not actual proof through measures.

This thread, for example, as started by @jabbr, has kept to a fairly reasonable level of discussion in terms of avoiding esoteric claims of "massive" improvements, and sticking to technical matters which actually have at least some degree of technical merit behind them.  There already is a place on these forums reserved for outrageous claims of "massive" improvements which have no solid basis in their technical merit, which is fine with me.    

[barrows]

1 minute ago, lmitche said:

Barrows, why do you use SMF vs MMF from the Sonore OM to Signature Rendu SE Optical?

yes, I am using SMF with Cisco LX SFP transceivers.

[barrows]

6 minutes ago, lmitche said:

Can you please share why you chose SMF SFPs and fiber over MMF SFPs and fiber?

Because some have suggested that there are advantages to using SMF, and it is easy to try.  It did not sound worse, but there was not any notable improvement either.  I did not do strict, level matched, careful A/B comparisons either, so there may be a small difference, but nothing really very significant here.

[barrows]

@lmitche, no need to stop posting here, I would like to continue to hear about your experiences with optical network configurations.  And I have nothing against subjective evaluations either, just that when we get into areas which are really esoteric, i would think a bit of restraint is in order.  As one who works with a manufacturer of Network based audio products, it important to understand where I am coming from.  Threads, such as the "massive" thread, while they may be very interesting for the devoted participants there, are very intimidating to potential customers looking to switch to Ethernet distributed audio.  A lot of potential customers looking to set up an Ethernet based system take one brief look at that thread, and turn their backs on the idea of implementing an Ethernet based system.  I mean, and they start asking questions like: do I need a Mutec clock master to slave all my Ethernet gear to!  Imagine how intimidating that can be to someone new to Ethernet distributed audio.

 

All I am  saying is that absolute statements, such as power supply perturbations are always going to result in sound quality issues, could perhaps be prefaced with: "IME", or "in my system".  When I hear these remarks about gear upstream of the optical fiber isolation, my own eyebrows raise a bit.  This does not mean I feel such is "impossible", just that it is unlikely, and needs to be verified by a bit more than only subjective means before suggesting that it is "fact".

 

My question when one raises this possibility is: then what are the implications for audio streams from the internet, like Tidal or Qobuz ?  I am sure they are not using silver gold alloy DC cables, for example, for all of their DC supplies, probably not using Mutec level clock generators either, and there is likely not a single linear power supply in the path from their servers to one's home.  Not to mention the accumulating clock phase noise of the hundreds of clocks the data encounters along the way...  

Now I play only local files here anyway, myself, so i do not know if Tidal and Qobuz hi res. are just as unlistenable as I find 128 Kb/s MP3, perhaps they are...

[barrows]

18 minutes ago, jabbr said:

The new SFP28 parts are backward compatible with SFP(+) and I am seeing a trend where they supply 25Gbe, 10Gbe, 5Gbe, 2.5Gbe and 1Gbe so I assume that when run at 1Gbe, these NICs, SFP28 modules get the same low noise board layout, low noise onboard power, low noise onboard clocks etc etc etc 

Oh, please excuse my pestering and ignorance, but i want to be perfectly clear on this before i make a purchase error:

 

You are saying that SFP+ modules (I have seen that they appear to be able to work at both 10 Gbe and 1 Gbe) will work in regular (non +) SFP cages, right?  So then one can have the extra precision and perhaps low noise benefit of the 10 Gbe transceivers, ruling at lower speed in a  1 Gbe environment, for, perhaps an even greater noise benefit.  I also need to be able to advise Sonore customers, so i "cannot" afford to be wrong in this (Sonore optical products use standard Gigabit SFP cages).

 

Thanks! 

[barrows]

2 hours ago, R1200CL said:

https://www.whatsbestforum.com/threads/taiko-audio-sgm-extreme-the-crème-de-la-crème.27433/page-58#post-596794
 

https://www.whatsbestforum.com/threads/taiko-audio-sgm-extreme-the-crème-de-la-crème.27433/page-177#post-645071
 

I would advise that folks do not believe all that they read, and do your own comparisons, in your system.  Additionally, a degree of technical understanding of how and why different approaches might make sonic differences can be very helpful in sorting things out.

Anyone can find, and re-post, opinions on the Internet to support just about any point of view, especially when we are talking about entirely subjective observations.

[barrows]

9 minutes ago, R1200CL said:

 You may (dis)like this post:

Maybe we bring different switches to your $8000 challenge 😀

Or perhaps, if one looks at this excerpt:

 

"You can do that same test in my system, and although you disconnect the cable while playing, the buffered tracks using the switch with the upgraded clock sound much better. In other words, even if you disconnect the network cable, whatever good or bad things your network does is already embedded in the buffered track somehow. Don't ask me how or why... I wish I could explain all that, but I can't. 

Sorry to tell you that, but I don't agree with your simple theory. I wish it was that simple, but it's a lot more complex than that."

 

One might conclude that the "massive" improvement is actually imaginary.  When a person proposes an improvement with no possible actual technical explanation for such, an observer must be allowed to suspect that the "improvement" was not actually real.  The upstream clock in the switch is gone and technically cannot have any further influence on the sound quality once the file data is in the downstream buffer, and the Ethernet cable is unplugged.  The clock in the switch is not "embedded" in the data somehow, that clock is long gone when the data is in the downstream buffer, as data in a buffer has no clock reference at that point.  John Swenson has speculated that upstream clock phase noise does matter to downstream playback, but this can only happen when the Ethernet cable is in place (and is still unproven speculation).  This is one of those cases where I would suggest that extra ordinary claims require extraordinary proof.

 

Consider: if there was somehow a way which an Ethernet timing clock "embedded" its phase noise/jitter in the data, then the internet would not work because all of the accumulating clock jitter over hundreds, or even thousands of re-clocking steps would so corrupt the data as for it to become unintelligible.  The same could be said of streaming audio from the likes of Qobuz-if clock jitter is accumulating and "embedding" itself in the data, the sound quality of streaming audio would be hopelessly corrupted due to the hundreds of re-clocking steps on the way from the Qobuz servers to one's home (and indeed, I very much doubt also that these clocks are ultra low jitter ones, or that the power supplies used for the internet path from Qobuz to one's home are SJ designs, or even linear for that matter).

[barrows]

9 minutes ago, ASRMichael said:

Can you prove it’s not? If not why not? 

When person(s) make extraordinary claims which are completely contrary to how Network data transfers actually work in a technical sense, then the onus for "proof' would fall on the person making the extraordinary claim, not on the person suggesting that the claim is unsupported by any reasonable technical explanation.

[barrows]

45 minutes ago, ASRMichael said:

I agree, but also disagree. Why? Because you can’t prove it either way. Is it not because we don’t have the right measurement tools yet? It works both ways as far as I’m concerned. 
 

 

I do not agree that many of these things cannot be proved, although proving a negative is virtually impossible, proving a positive improvement should be very possible.  The measurement tools certainly do exist for this, as we have measurements which can resolve many things well below the threshold of audibility; the real challenge in proving things is figuring out exactly what to measure.

This is an old problem, with a bit of a new paradigm on it from the current state of affairs in the US: unfortunately our culture here in the US has, in the past few years, embraced a concept of there being no such thing as an actual, objective fact at all.  And this concept has very unfortunately spread to many endeavors and experiences. While I embrace the notion of being open minded, that is not the same thing as dismissing actual facts which are objective and well established.  If a person seeking advancement in any endeavor dismisses actual, established, objective facts, they are left with nothing; no basis from which to proceed, and this is a very dangerous place to be indeed, as one ends up merely randomly trying things in an effort to make progress.

 

While I would readily admit that we do not know everything which affects audio playback performance objectively, not knowing everything does not mean that we know nothing.  Dismissing objective facts as to how electronics actually operate is not a way forward, it just leads to madness and sideways, or even backwards movement.

 

As to an example of "proof" of an improvement, I would accept a blinded listening test as proof, if it was properly conducted and returned a result better than 80% in a trial of 20 tests.  This could be achieved without the need to establish new measurement protocols.  

[barrows]

30 minutes ago, R1200CL said:

Barrows, you should know better than writing this. 
We’re not debating that Ethernet is error free. It is by definition. No one question that. 
(Well some do). Even if there is one or two bit errors, it doesn’t affect SQ. And you know it. 
 

Since we’re not discussing critical time synchronization over long distances, like the White Rabit project, let’s also keep the discussion after what’s happening your ISP modem. 
 

Also fiber will solve some issues, still it’s my understanding we are left with the phase noise issue, and possible some other gremlins that seems to be able to still travel with the digital signal. 
 

Q. What about fiber-optic interfaces? Don’t these block everything?

A. In the case of a pure optical input (zero metal connection), this does block leakage current, but it does not block phase-noise affects. The optical connection is like any other isolator: jitter on the input is transmitted down the fiber and shows up at the receiver. If the receiver reclocks the data with a local clock, you still have the effects of the ground plane-noise from the data causing threshold changes on the reclocking circuit, thus overlaying on top of the local clock.

I did not mention anything about data errors, and I fully agree that I do not think anyone here is suggesting that data errors are to blame for the SQ differences which some claim to perceive.  My objection is to the use of the terminology that somehow, some mysterious "thing/problem" is "embedded" in the data.  There is nothing "embedded" in the data when it goes into a receiving buffer, the data is perfect, and it contains nothing in terms of clocking, as their is no clock in the buffer, just the perfect data and nothing else.  Data is clocked into the buffer, and clocked out of the buffer, but there is no trace of either of these clocks "embedded" in the data itself.

As to JS' speculations regarding clock phase noise, this has not been adequately explained by John such that I can comprehend what he is suggesting might be at play (and this is only theory and entirely unproven at this point).  

[barrows]

1 hour ago, R1200CL said:

What size is the buffer in opticalRendu and it must have neen a good reason copied it to microRendu 1.5 ?
By size, I suppose time is interesting to, but I think I have sound one or two seconds after pulling the plug.

Any reason not to make the buffer bigger ? 

Buffer size used depends on the transfer protocol used (RAAT, DLNA, NAA, LMS) the are all different.  And some, like LMS allow for some adjustment of that.

That said, after having experimented with buffer sizes in the LMS settings, I struggled to hear any difference at all, to the point that the differences I might have heard could just as easily been imaginary.  If there were differences, there was certainly no clear conclusion: in other words, longer/bigger buffering was not superior.

As far as hardware buffer capability of the µR, uR, and oR, that would be proprietary and not something  Sonore would reveal to our competitors on a public forum.

 

"Any reason not to make the buffer bigger ?"

 

I would ask the following: Any reason to make the buffer bigger?

 

As long as one is not getting underruns, why would you desire a larger buffer?  There is no conceivable advantage to such which I can think of.  There are those who have reported on these forums that low latency is a desirable feature for playback software sound quality (but I can imagine no reason why it would actually matter) so from those persons perspective, buffering "should" be as little as possible...

[barrows]

35 minutes ago, Superdad said:

 

Hard to know if the compatibility issue lay with the MikroTik switch or their preterminated active optical cable. We have no intention of purchasing lots of switches, cables, and SFP transceivers to test combinations. (Such an undertaking would bring our modest firm to a halt. )

 

Our Hong Kong dealer AfterDark has tested and confirmed EtherREGEN compatibility with the Finisar AOCs, and he sells those:

https://www.adark.co/collections/uptone-audio/products/copy-of-afterdark-project-clayx-constellation-sfp-finisar-active-optical-cable-aoc

or folks can order the same from DigiKey:

https://www.digikey.com/en/products/detail/finisar-corporation/FCBG110SD1C01/4416195

Certainly inexpensive enough.

 

Given the report you made with regards to configuration issues and forcing the MikroTik switch to 1Gbe, I think you can see the sort of quagmire we would be dropping into if we attempted to support connections to specific models of other company's switches.

 

Sorry we can't be of more help in this. 

 

Hahaha yeah Alex no doubt!  There are an infinite number of possible combinations, and no company can be expected to test all of them.   And indeed, if a company did endeavor to start testing such things, inevitably customers would then start asking which set up sounds best, which would result in a much deeper rabbit hole to go down.  

[barrows]

1 hour ago, Foggie said:

My opticalrendu suffers from this, but when a win naa is attached those issue go away.  Sorry for a bit OT

Suffers from what, exactly?  Sonore opticalRendu should not have any problems passing native DSD to DACs which support that format, and there should not also be any annoying pops or clicks when playing back DSD.

BTW, there is no drawback to using DoP for days which require it, except for the limitation in available playback rate: using DoP has no compromise in sound quality.